Charleston County leans slightly Democratic by roughly 14 points: about 57% of voters vote Democratic and 43% Republican.
About 72% of adults in Charleston County typically vote, above the U.S. average of about 62%. Among adults in Charleston County, ~41% vote Democratic, ~31% Republican, and ~28% don't vote. The map below shows estimated turnout by block group.
How Charleston County compares
Among counties within 50 miles, Charleston County is the most Democratic-leaning.
Charleston County runs about 31 points more Democratic than South Carolina as a whole. South Carolina leans Republican overall, while Charleston County is one of the few Democratic-leaning pockets.
Politics vary noticeably by city within Charleston County. The north side runs the most Democratic (D+53) and the northeast side runs the most Republican (R+11), a spread of about 64 points.
Why Charleston County leans the way it does
This analysis examined 14,881 data points per county to find what predicts political lean and turnout. The items below are a few correlations that stood out for Charleston County, not a ranked or complete list of what matters most.
Areas with high college attainment vote Democratic. About 50% of adults in Charleston County hold a bachelor's degree, about 22 points above the U.S. average of 28%. Dense areas vote Democratic, and Charleston County sits in the top fifth on density (about 63%, above 87% of counties). Charleston County runs against the grain of South Carolina, a Democratic-leaning pocket in a Republican-leaning state.
Preventive-care access and voter turnout
Places with strong routine preventive-care access tend to turn out at a higher rate; Charleston County, SC sits in the top quarter nationally on this measure. Dental visits do not drive turnout; the rate reflects income, insurance, and healthcare access, which line up with who votes.
Why turnout in Charleston County looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Charleston County is in the top quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. The dental-visit rate here is about 67%, about 7 points above the U.S. average of 60%. Learn more about the findings and methodology on the political spectrum map.
Nearby Counties
- Berkeley County, SC R+13
- Dorchester County, SC R+12
- Colleton County, SC R+17
- Beaufort County, SC R+9
- Williamsburg County, SC D+26
- Georgetown County, SC R+17
- Clarendon County, SC R+8
- Orangeburg County, SC D+28
- Hampton County, SC D+9
- Jasper County, SC Even
Counties with Similar Populations
- Waukesha County, WI R+14
- Genesee County, MI D+8
- St. Charles County, MO R+14
- Placer County, CA R+11
- Mobile County, AL R+8
- Orange County, NY R+7
- Richland County, SC D+38
- Manatee County, FL R+15
- Pulaski County, AR D+28
- Loudoun County, VA D+18
Sources and methodology
Precinct-level voting records used to fit the model come from South Carolina State Election Commission, distributed by the Voting and Election Science Team. Demographic inputs come from the U.S. Census Bureau (ACS 5-year estimates and the 2020 Decennial Census). Health and environmental inputs come from the CDC (PLACES and the Environmental Justice Index). Land cover comes from the USGS and EPA. Election-day and lead-up weather come from PRISM 4km daily grids and the NOAA Global Historical Climatology Network. Mail-voting and election-administration patterns come from the MIT Election Lab's Survey of the Performance of American Elections. Block-group crime detail comes from CrimeGrade. Internet data and modeling support provided by ISPreports.org.
Modeling and analysis by the BestNeighborhood data science team. Full methodology and findings: political spectrum map.
Methodology reviewed by the BestNeighborhood data team. Last updated May 2026.